The present invention relates to the field of automotive window-actuators in general, and in particular to an improved universal window-actuator drive unit.
A window-actuator drive unit is a device that, when coupled to a window-actuator, provides up-down movement to open and close a window. Such a device is typically used to provide "power windows" in an automobile. A window-actuator to which a window-actuator drive unit may be connected is generally one of two types: cable pulley, and arm-scissor type. It is desirable to have a drive unit that is capable of being used interchangeably with either type of window-actuator; that is, a universal window-actuator drive unit.
A window-actuator drive unit of the type to which the improvement of the present invention relates is described in U.S. Pat. No. 5,095,766 to Knappe et al., which is incorporated herein by reference, and its counterpart European application EP-B1-0 360 912. The '766 drive unit is universal in that it may be used both with a cable pulley window-actuator and an arm-scissors type window-actuator. This flexibility is provided by a specially adapted shaft collar coupled to the driving disk of the drive unit. The shaft collar is equipped with an outer grooved toothing capable of establishing an interlocking rotational-slave relationship with a cable pulley component of a cable pulley window-actuator or with a driving pinion of an arm-scissors type window-actuator, both of which have a corresponding inner grooved toothing.
Although the window-actuator drive unit of the '766 patent works well, it would be beneficial to have a universal window-actuator drive unit that is substantially more compact without sacrificing efficiency of operation. A further requirement of such a device is that it continue to perform under the high impacts and shock stresses likely to arise from automotive use.